1. 15 2月, 2012 1 次提交
    • S
      USB: Don't fail USB3 probe on missing legacy PCI IRQ. · 68d07f64
      Sarah Sharp 提交于
      Intel has a PCI USB xhci host controller on a new platform. It doesn't
      have a line IRQ definition in BIOS.  The Linux driver refuses to
      initialize this controller, but Windows works well because it only depends
      on MSI.
      
      Actually, Linux also can work for MSI.  This patch avoids the line IRQ
      checking for USB3 HCDs in usb core PCI probe.  It allows the xHCI driver
      to try to enable MSI or MSI-X first.  It will fail the probe if MSI
      enabling failed and there's no legacy PCI IRQ.
      
      This patch should be backported to kernels as old as 2.6.32.
      Signed-off-by: NAlex Shi <alex.shi@intel.com>
      Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
      Cc: stable@vger.kernel.org
      68d07f64
  2. 10 12月, 2011 2 次提交
    • A
      USB: Adding #define in hub_configure() and hcd.c file · 7bf01185
      Aman Deep 提交于
      This patch is in succession of previous patch
      commit c8421147
              xHCI: Adding #define values used for hub descriptor
      
      Hub descriptors characteristics #defines values are added in
      hub_configure() in place of magic numbers as asked by Alan Stern.
      And the indentation for switch and case is changed to be same.
      
      Some #defines values are added in ch11.h for defining hub class
      protocols and used in hub.c and hcd.c in which magic values were
      used for hub class protocols.
      Signed-off-by: NAman Deep <amandeep3986@gmail.com>
      Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>
      7bf01185
    • C
      usb: fix number of mapped SG DMA entries · bc677d5b
      Clemens Ladisch 提交于
      Add a new field num_mapped_sgs to struct urb so that we have a place to
      store the number of mapped entries and can also retain the original
      value of entries in num_sgs.  Previously, usb_hcd_map_urb_for_dma()
      would overwrite this with the number of mapped entries, which would
      break dma_unmap_sg() because it requires the original number of entries.
      
      This fixes warnings like the following when using USB storage devices:
       ------------[ cut here ]------------
       WARNING: at lib/dma-debug.c:902 check_unmap+0x4e4/0x695()
       ehci_hcd 0000:00:12.2: DMA-API: device driver frees DMA sg list with different entry count [map count=4] [unmap count=1]
       Modules linked in: ohci_hcd ehci_hcd
       Pid: 0, comm: kworker/0:1 Not tainted 3.2.0-rc2+ #319
       Call Trace:
        <IRQ>  [<ffffffff81036d3b>] warn_slowpath_common+0x80/0x98
        [<ffffffff81036de7>] warn_slowpath_fmt+0x41/0x43
        [<ffffffff811fa5ae>] check_unmap+0x4e4/0x695
        [<ffffffff8105e92c>] ? trace_hardirqs_off+0xd/0xf
        [<ffffffff8147208b>] ? _raw_spin_unlock_irqrestore+0x33/0x50
        [<ffffffff811fa84a>] debug_dma_unmap_sg+0xeb/0x117
        [<ffffffff8137b02f>] usb_hcd_unmap_urb_for_dma+0x71/0x188
        [<ffffffff8137b166>] unmap_urb_for_dma+0x20/0x22
        [<ffffffff8137b1c5>] usb_hcd_giveback_urb+0x5d/0xc0
        [<ffffffffa0000d02>] ehci_urb_done+0xf7/0x10c [ehci_hcd]
        [<ffffffffa0001140>] qh_completions+0x429/0x4bd [ehci_hcd]
        [<ffffffffa000340a>] ehci_work+0x95/0x9c0 [ehci_hcd]
        ...
       ---[ end trace f29ac88a5a48c580 ]---
       Mapped at:
        [<ffffffff811faac4>] debug_dma_map_sg+0x45/0x139
        [<ffffffff8137bc0b>] usb_hcd_map_urb_for_dma+0x22e/0x478
        [<ffffffff8137c494>] usb_hcd_submit_urb+0x63f/0x6fa
        [<ffffffff8137d01c>] usb_submit_urb+0x2c7/0x2de
        [<ffffffff8137dcd4>] usb_sg_wait+0x55/0x161
      Signed-off-by: NClemens Ladisch <clemens@ladisch.de>
      Cc: stable <stable@vger.kernel.org>
      Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>
      bc677d5b
  3. 15 11月, 2011 1 次提交
    • A
      USB: Remove the SAW_IRQ hcd flag · 968b822c
      Alan Stern 提交于
      The HCD_FLAG_SAW_IRQ flag was introduced in order to catch IRQ routing
      errors: If an URB was unlinked and the host controller hadn't gotten
      any IRQs, it seemed likely that the IRQs were directed to the wrong
      vector.
      
      This warning hasn't come up in many years, as far as I know; interrupt
      routing now seems to be well under control.  Therefore there's no
      reason to keep the flag around any more.  This patch (as1495) finally
      removes it.
      Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
      Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>
      968b822c
  4. 19 10月, 2011 1 次提交
    • S
      xHCI/USB: Make xHCI driver have a BOS descriptor. · 48e82361
      Sarah Sharp 提交于
      To add USB 3.0 link power management (LPM), we need to know what the U1
      and U2 exit latencies are for the xHCI host controller.  External USB 3.0
      hubs report these values through the SuperSpeed Capabilities descriptor in
      the BOS descriptor.  Make the USB 3.0 roothub for the xHCI host behave
      like an external hub and return the BOS descriptors.
      
      The U1 and U2 exit latencies will vary across each host controller, so we
      need to dynamically fill those values in by reading the exit latencies out
      of the xHC registers.  Make the roothub code in the USB core handle
      hub_control() returning the length of the data copied.
      Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
      Acked-by: NAlan Stern <stern@rowland.harvard.edu>
      Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>
      48e82361
  5. 28 9月, 2011 1 次提交
  6. 27 9月, 2011 1 次提交
    • A
      USB: Update USB default wakeup settings · a6eeeb9f
      Alan Stern 提交于
      This patch (as1486) implements the kernel's new wakeup policy for USB
      host controllers.  Since they don't generate wakeup requests on their
      but merely forward requests from their root hubs toward the CPU, they
      should be enabled for wakeup by default.
      
      Also, to be compliant with both the old and new policies, root hubs
      should not be enabled for remote wakeup by default.  Userspace must
      enable it explicitly if it is desired.
      Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
      Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>
      a6eeeb9f
  7. 20 8月, 2011 1 次提交
  8. 16 8月, 2011 1 次提交
  9. 07 6月, 2011 1 次提交
  10. 20 5月, 2011 1 次提交
    • A
      USB: remove remaining usages of hcd->state from usbcore and fix regression · 69fff59d
      Alan Stern 提交于
      This patch (as1467) removes the last usages of hcd->state from
      usbcore.  We no longer check to see if an interrupt handler finds that
      a controller has died; instead we rely on host controller drivers to
      make an explicit call to usb_hc_died().
      
      This fixes a regression introduced by commit
      9b37596a (USB: move usbcore away from
      hcd->state).  It used to be that when a controller shared an IRQ with
      another device and an interrupt arrived while hcd->state was set to
      HC_STATE_HALT, the interrupt handler would be skipped.  The commit
      removed that test; as a result the current code doesn't skip calling
      the handler and ends up believing the controller has died, even though
      it's only temporarily stopped.  The solution is to ignore HC_STATE_HALT
      following the handler's return.
      
      As a consequence of this change, several of the host controller
      drivers need to be modified.  They can no longer implicitly rely on
      usbcore realizing that a controller has died because of hcd->state.
      The patch adds calls to usb_hc_died() in the appropriate places.
      
      The patch also changes a few of the interrupt handlers.  They don't
      expect to be called when hcd->state is equal to HC_STATE_HALT, even if
      the controller is still alive.  Early returns were added to avoid any
      confusion.
      Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
      Tested-by: NManuel Lauss <manuel.lauss@googlemail.com>
      CC: Rodolfo Giometti <giometti@linux.it>
      CC: Olav Kongas <ok@artecdesign.ee>
      CC: <stable@kernel.org>
      Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>
      69fff59d
  11. 30 4月, 2011 1 次提交
  12. 14 4月, 2011 1 次提交
    • M
      USB: Fix unplug of device with active streams · b214f191
      Matthew Wilcox 提交于
      If I unplug a device while the UAS driver is loaded, I get an oops
      in usb_free_streams().  This is because usb_unbind_interface() calls
      usb_disable_interface() which calls usb_disable_endpoint() which sets
      ep_out and ep_in to NULL.  Then the UAS driver calls usb_pipe_endpoint()
      which returns a NULL pointer and passes an array of NULL pointers to
      usb_free_streams().
      
      I think the correct fix for this is to check for the NULL pointer
      in usb_free_streams() rather than making the driver check for this
      situation.  My original patch for this checked for dev->state ==
      USB_STATE_NOTATTACHED, but the call to usb_disable_interface() is
      conditional, so not all drivers would want this check.
      
      Note from Sarah Sharp: This patch does avoid a potential dereference,
      but the real fix (which will be implemented later) is to set the
      .soft_unbind flag in the usb_driver structure for the UAS driver, and
      all drivers that allocate streams.  The driver should free any streams
      when it is unbound from the interface.  This avoids leaking stream rings
      in the xHCI driver when usb_disable_interface() is called.
      
      This should be queued for stable trees back to 2.6.35.
      Signed-off-by: NMatthew Wilcox <willy@linux.intel.com>
      Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
      Cc: stable@kernel.org
      b214f191
  13. 31 3月, 2011 1 次提交
  14. 14 3月, 2011 8 次提交
    • S
      USB: Set usb_hcd->state and flags for shared roothubs. · ff9d78b3
      Sarah Sharp 提交于
      The hcd->flags are in a sorry state.  Some of them are clearly specific to
      the particular roothub (HCD_POLL_RH, HCD_POLL_PENDING, and
      HCD_WAKEUP_PENDING), but some flags are related to PCI device state
      (HCD_HW_ACCESSIBLE and HCD_SAW_IRQ).  This is an issue when one PCI device
      can have two roothubs that share the same IRQ line and hardware.
      
      Make sure to set HCD_FLAG_SAW_IRQ for both roothubs when an interrupt is
      serviced, or an URB is unlinked without an interrupt.  (We can't tell if
      the host actually serviced an interrupt for a particular bus, but we can
      tell it serviced some interrupt.)
      
      HCD_HW_ACCESSIBLE is set once by usb_add_hcd(), which is set for both
      roothubs as they are added, so it doesn't need to be modified.
      HCD_POLL_RH and HCD_POLL_PENDING are only checked by the USB core, and
      they are never set by the xHCI driver, since the roothub never needs to be
      polled.
      
      The usb_hcd's state field is a similar mess.  Sometimes the state applies
      to the underlying hardware: HC_STATE_HALT, HC_STATE_RUNNING, and
      HC_STATE_QUIESCING.  But sometimes the state refers to the roothub state:
      HC_STATE_RESUMING and HC_STATE_SUSPENDED.
      
      Alan Stern recently made the USB core not rely on the hcd->state variable.
      Internally, the xHCI driver still checks for HC_STATE_SUSPENDED, so leave
      that code in.  Remove all references to HC_STATE_HALT, since the xHCI
      driver only sets and doesn't test those variables.  We still have to set
      HC_STATE_RUNNING, since Alan's patch has a bug that means the roothub
      won't get registered if we don't set that.
      
      Alan's patch made the USB core check a different variable when trying to
      determine whether to suspend a roothub.  The xHCI host has a split
      roothub, where two buses are registered for one PCI device.  Each bus in
      the xHCI split roothub can be suspended separately, but both buses must be
      suspended before the PCI device can be suspended.  Therefore, make sure
      that the USB core checks HCD_RH_RUNNING() for both roothubs before
      suspending the PCI host.
      Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
      ff9d78b3
    • S
      usb: Make core allocate resources per PCI-device. · c5635437
      Sarah Sharp 提交于
      Introduce the notion of a PCI device that may be associated with more than
      one USB host controller driver (struct usb_hcd).  This patch is the start
      of the work to separate the xHCI host controller into two roothubs: a USB
      3.0 roothub with SuperSpeed-only ports, and a USB 2.0 roothub with
      HS/FS/LS ports.
      
      One usb_hcd structure is designated to be the "primary HCD", and a pointer
      is added to the usb_hcd structure to keep track of that.  A new function
      call, usb_hcd_is_primary_hcd() is added to check whether the USB hcd is
      marked as the primary HCD (or if it is not part of a roothub pair).  To
      allow the USB core and xHCI driver to access either roothub in a pair, a
      "shared_hcd" pointer is added to the usb_hcd structure.
      
      Add a new function, usb_create_shared_hcd(), that does roothub allocation
      for paired roothubs.  It will act just like usb_create_hcd() did if the
      primary_hcd pointer argument is NULL.  If it is passed a non-NULL
      primary_hcd pointer, it sets usb_hcd->shared_hcd and usb_hcd->primary_hcd
      fields.  It will also skip the bandwidth_mutex allocation, and set the
      secondary hcd's bandwidth_mutex pointer to the primary HCD's mutex.
      
      IRQs are only allocated once for the primary roothub.
      
      Introduce a new usb_hcd driver flag that indicates the host controller
      driver wants to create two roothubs.  If the HCD_SHARED flag is set, then
      the USB core PCI probe methods will allocate a second roothub, and make
      sure that second roothub gets freed during rmmod and in initialization
      error paths.
      
      When usb_hc_died() is called with the primary HCD, make sure that any
      roothubs that share that host controller are also marked as being dead.
      Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
      c5635437
    • S
      usb: Store bus type in usb_hcd, not in driver flags. · 83de4b2b
      Sarah Sharp 提交于
      The xHCI driver essentially has both a USB 2.0 and a USB 3.0 roothub.  So
      setting the HCD_USB3 bits in the hcd->driver->flags is a bit misleading.
      Add a new field to usb_hcd, bcdUSB.  Store the result of
      hcd->driver->flags & HCD_MASK in it.  Later, when we have the xHCI driver
      register the two roothubs, we'll set the usb_hcd->bcdUSB field to HCD_USB2
      for the USB 2.0 roothub, and HCD_USB3 for the USB 3.0 roothub.
      Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
      83de4b2b
    • S
      usb: Change usb_hcd->bandwidth_mutex to a pointer. · d673bfcb
      Sarah Sharp 提交于
      Change the bandwith_mutex in struct usb_hcd to a pointer.  This will allow
      the pointer to be shared across usb_hcds for the upcoming work to split
      the xHCI driver roothub into a USB 2.0/1.1 and a USB 3.0 bus.
      Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
      d673bfcb
    • S
      usb: Refactor irq enabling out of usb_add_hcd() · 23e0d106
      Sarah Sharp 提交于
      Refactor out the code in usb_add_hcd() to request the IRQ line for the
      HCD.  This will only need to be called once for the two xHCI roothubs, so
      it's easier to refactor it into a function, rather than wrapping the long
      if-else block into another if statement.
      Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
      23e0d106
    • S
      usb: Make USB 3.0 roothub have a SS EP comp descriptor. · 22c6a35d
      Sarah Sharp 提交于
      Make the USB 3.0 roothub registered by the USB core have a SuperSpeed
      Endpoint Companion Descriptor after the interrupt endpoint.  All USB 3.0
      devices are required to have this, and the USB 3.0 bus specification
      (section 10.13.1) says which values the descriptor should have.
      Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
      22c6a35d
    • S
      usb: Initialize hcd->state roothubs. · 4814030c
      Sarah Sharp 提交于
      We would like to allow host controller drivers to stop using hcd->state.
      Unfortunately, some host controller drivers use hcd->state as an
      implicit way of telling the core that a controller has died.  The
      roothub registration functions must assume the host died if hcd->state
      equals HC_STATE_HALT.
      
      To facilitate drivers that don't want to set hcd->state to
      HC_STATE_RUNNING in their initialization routines, we set the state to
      running before calling the host controller's start function.
      Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
      4814030c
    • S
      USB: Fix usb_add_hcd() checkpatch errors. · abc4f9b0
      Sarah Sharp 提交于
      The irq enabling code is going to be refactored into a new function, so
      clean up some checkpatch errors before moving it.
      Signed-off-by: NSarah Sharp <sarah.a.sharp@linux.intel.com>
      abc4f9b0
  15. 08 3月, 2011 1 次提交
    • A
      USB: move usbcore away from hcd->state · 9b37596a
      Alan Stern 提交于
      The hcd->state variable is a disaster.  It's not clearly owned by
      either usbcore or the host controller drivers, and they both change it
      from time to time, potentially stepping on each other's toes.  It's
      not protected by any locks.  And there's no mechanism to prevent it
      from going through an invalid transition.
      
      This patch (as1451) takes a first step toward fixing these problems.
      As it turns out, usbcore uses hcd->state for essentially only two
      things: checking whether the controller's root hub is running and
      checking whether the controller has died.  Therefore the patch adds
      two new atomic bitflags to the hcd structure, to store these pieces of
      information.  The new flags are used only by usbcore, and a private
      spinlock prevents invalid combinations (a dead controller's root hub
      cannot be running).
      
      The patch does not change the places where usbcore sets hcd->state,
      since HCDs may depend on them.  Furthermore, there is one place in
      usb_hcd_irq() where usbcore still must use hcd->state: An HCD's
      interrupt handler can implicitly indicate that the controller died by
      setting hcd->state to HC_STATE_HALT.  Nevertheless, the new code is a
      big improvement over the current code.
      
      The patch makes one other change.  The hcd_bus_suspend() and
      hcd_bus_resume() routines now check first whether the host controller
      has died; if it has then they return immediately without calling the
      HCD's bus_suspend or bus_resume methods.
      
      This fixes the major problem reported in Bugzilla #29902: The system
      fails to suspend after a host controller dies during system resume.
      Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
      Tested-by: NAlex Terekhov <a.terekhov@gmail.com>
      CC: <stable@kernel.org>
      Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>
      9b37596a
  16. 05 2月, 2011 2 次提交
  17. 04 2月, 2011 1 次提交
  18. 22 11月, 2010 1 次提交
    • A
      usb: musb: do not use dma for control transfers · 07a8cdd2
      Anand Gadiyar 提交于
      The Inventra DMA engine used with the MUSB controller in many
      SoCs cannot use DMA for control transfers on EP0, but can use
      DMA for all other transfers.
      
      The USB core maps urbs for DMA if hcd->self.uses_dma is true.
      (hcd->self.uses_dma is true for MUSB as well).
      
      Split the uses_dma flag into two - one that says if the
      controller needs to use PIO for control transfers, and
      another which says if the controller uses DMA (for all
      other transfers).
      
      Also, populate this flag for all MUSB by default.
      
      (Tested on OMAP3 and OMAP4 boards, with EHCI and MUSB HCDs
      simultaneously in use).
      Signed-off-by: NMaulik Mankad <x0082077@ti.com>
      Signed-off-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>
      Signed-off-by: NAnand Gadiyar <gadiyar@ti.com>
      Cc: Oliver Neukum <oliver@neukum.org>
      Cc: Alan Stern <stern@rowland.harvard.edu>
      Cc: Praveena NADAHALLY <praveen.nadahally@stericsson.com>
      Cc: Ajay Kumar Gupta <ajay.gupta@ti.com>
      Signed-off-by: NFelipe Balbi <balbi@ti.com>
      07a8cdd2
  19. 17 11月, 2010 1 次提交
  20. 23 10月, 2010 2 次提交
  21. 11 8月, 2010 6 次提交
    • D
      USB: xHCI: Supporting MSI/MSI-X · 43b86af8
      Dong Nguyen 提交于
      Enable MSI/MSI-X supporting in xhci driver.
      
      Provide the mechanism to fall back using MSI and Legacy IRQs
      if MSI-X IRQs register failed.
      Signed-off-by: NDong Nguyen <Dong.Nguyen@amd.com>
      Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>,
      Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>
      43b86af8
    • A
      USB: EHCI: fix NULL pointer dererence in HCDs that use HCD_LOCAL_MEM · 4307a28e
      Andrea Righi 提交于
      If we use the HCD_LOCAL_MEM flag and dma_declare_coherent_memory() to
      enforce the host controller's local memory utilization we also need to
      disable native scatter-gather support, otherwise hcd_alloc_coherent() in
      map_urb_for_dma() is called with urb->transfer_buffer == NULL, that
      triggers a NULL pointer dereference.
      
      We can also consider to add a WARN_ON() and return an error code to
      better catch this problem in the future.
      
      At the moment no driver seems to hit this bug, so I should
      consider this a low-priority fix.
      Signed-off-by: NAndrea Righi <arighi@develer.com>
      Acked-by: NAlan Stern <stern@rowland.harvard.edu>
      Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>
      4307a28e
    • A
      USB: fix race between root-hub wakeup & controller suspend · ff2f0787
      Alan Stern 提交于
      This patch (as1395) adds code to hcd_pci_suspend() for handling wakeup
      races.  This is another general race pattern, similar to the "open
      vs. unregister" race we're all familiar with.  Here, the race is
      between suspending a device and receiving a wakeup request from one of
      the device's suspended children.
      
      In particular, if a root-hub wakeup is requested at about the same
      time as the corresponding USB controller is suspended, and if the
      controller is enabled for wakeup, then the controller should either
      fail to suspend or else wake right back up again.
      
      During system sleep this won't happen very much, especially since host
      controllers generally aren't enabled for wakeup during sleep.  However
      it is definitely an issue for runtime PM.  Something like this will be
      needed to prevent the controller from autosuspending while waiting for
      a root-hub resume to take place.  (That is, in fact, the common case,
      for which there is an extra test.)
      Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
      Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>
      ff2f0787
    • A
      USB: convert usb_hcd bitfields into atomic flags · 541c7d43
      Alan Stern 提交于
      This patch (as1393) converts several of the single-bit fields in
      struct usb_hcd to atomic flags.  This is for safety's sake; not all
      CPUs can update bitfield values atomically, and these flags are used
      in multiple contexts.
      
      The flag fields that are set only during registration or removal can
      remain as they are, since non-atomic accesses at those times will not
      cause any problems.
      
      (Strictly speaking, the authorized_default flag should become atomic
      as well.  I didn't bother with it because it gets changed only via
      sysfs.  It can be done later, if anyone wants.)
      Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
      Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>
      541c7d43
    • A
      USB: don't stop root-hub status polls too soon · 6d88e679
      Alan Stern 提交于
      This patch (as1390) fixes a problem that crops up when a UHCI host
      controller is unbound from uhci-hcd while there are still some active
      URBs.  The URBs have to be unlinked when the root hub is unregistered,
      and uhci-hcd relies upon root-hub status polls as part of its
      unlinking procedure.  But usb_hcd_poll_rh_status() won't make those
      status calls if hcd->rh_registered is clear, and the flag is cleared
      _before_ the unregistration takes place.
      
      Since hcd->rh_registered is used for other things and needs to be
      cleared early, the solution is to add a new flag (rh_pollable) and use
      it instead.  It gets cleared _after_ the root hub is unregistered.
      
      Now that the status polls don't end too soon, we have to make sure
      they also don't occur too late -- after the root hub's usb_device
      structure or the HCD's private structures are deallocated.  Therefore
      the patch adds usb_get_device() and usb_put_device() calls to protect
      the root hub structure, and it adds an extra del_timer_sync() to
      prevent the root-hub timer from causing an unexpected status poll.
      
      This additional complexity would not be needed if the HCD framework
      had provided separate stop() and release() callbacks instead of just
      stop().  This lack could be fixed at some future time (although it
      would require changes to every host controller driver); when that
      happens this patch won't be needed any more.
      Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
      Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>
      6d88e679
    • A
      USB: fix failure path in usb_add_hcd() · 96e077ae
      Alan Stern 提交于
      This patch (as1389) fixes some errors in the failure pathway of
      usb_add_hcd().  The actions it takes ought to be exactly the same as
      those taken by usb_remove_hcd(), but they aren't.
      
      In one case (removal of the usb_bus_attr_group), the two routines are
      brought into agreement by changing usb_remove_hcd().  All the other
      discrepancies are fixed by changing usb_add_hcd().
      Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
      Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>
      96e077ae
  22. 21 5月, 2010 4 次提交